In operation of optical systems with a globally or locally high level of luminous power density, a problem which arises is that the increase in temperature in the optical elements, such as, for example, lenses and the associated holder elements, that is linked to the high level of luminous power density and absorption for example at layers, leads to expansion or deformation phenomena with respect to the elements and/or convection flows in existing intermediate spaces, which in turn results in the imaging properties being adversely affected.
In addition, at high levels of luminous power adverse effects on the illumination or imaging process occur to an increased degree due to stray light which for example has an influence on the imaging properties that can no longer be disregarded, such as, for example, at a diffractive optical element as is used for instance in a microlithographic projection exposure apparatus.
WO 2006/128613 A1 discloses inter alia a projection objective of a microlithographic projection exposure apparatus which has at least three subsystems as well as a beam deflection device arranged between the first and second subsystems. At least one screen is provided in the region of the beam deflection device to reduce direct transfer of stray light from the first subsystem into the third subsystem.
DE 102 10 893 A1 discloses inter alia an optical arrangement having an optical component which is disposed in a housing, in particular an aperture member. The component has an optically active first region and an optically inactive second region which at least partially surrounds the first region. Connected to the optically inactive second region is a thermally conductive element to dissipate heat from the housing to a heat radiating body in order to reduce a thermal drift of the characteristic of the optical system that is linked to an increase in temperature of the aperture member.
WO 2005/109104 A2 discloses inter alia an optical component having an optically active element and a holding element which is heat-conductingly connected thereto. The holding element has an active cooling system for dissipating heat from the optical element.